False Ilex Hairstreak Butterfly - Satyrium esculi

The False Ilex Hairstreak is very similar to the Ilex hairstreak Satyrium ilicis, but the two can be separated by careful examination of the patterns on the underwings.

Distribution

Not found in Britain, the False Ilex Hairstreak is a butterfly of Portugal, Spain, the extreme south of France and parts of northern Africa. Its grey-brown wings (wingspan 3 to 3.4cm) bear a broken white line. Under the hindwing is a row reddish-orange spots near to the outer edge.

Like other embers of the Satyrium genus, the False Ilex Hairstreak closes its wings as soon as it alights, so that the uppersides of the wings, which are plain brown, are rarely seen. The Ilex Hairstreak, Satyrium ilicis, is similar but its wings are a darker chocolate brown.

(Picture: Rob Petley-Jones)

Lifecycle

The larval foodplants of the False Ilex Hairstreak are low-growing scrub oaks, Quercus species. Its caterpillars are green, about 2cm when fully grown, and broad at the head tapering towards the tail.

The butterflies can be seen flyinh between May and August, and the youong larvae overwinter inside their eggs.